principal

noun
  1. The head or leader of a school, college, or other educational institution. noun
    The principal addressed the students during the assembly.
    She was promoted to the position of principal after years of teaching.
  2. A person who has controlling authority or is in a leading position, especially in a business or organization. noun
    The principal of the firm made the final decision on the merger.
    As a principal in the company, he has a significant say in its operations.
  3. The original sum of money borrowed or invested, excluding any interest or dividends. noun
    She paid off the principal of her loan over five years.
    Investors are primarily concerned with the return on their principal.
  4. Most important, consequential, or influential. adjective
    The principal reason for the meeting was to discuss budget cuts.
    Her principal concern was the safety of the children.